Let-off mechanism for pile-fabric looms.



No. 65!,321. Patented lune 5,190.0.

C. ALVORD. LET-OFF MECHANISM FOR PlLE FABRIC LOOMS.

(Application filed Dec. 81, 1897.) N o M o d e l &

in: ripams PETERS cu. vnoroumo, WASHINGTON,

UNr'rEn STATES PATENT OFFICE. I

CLINTON ALVORD, OF WORCESTER, MASSACHUSETTS.

LET-OFF MECHANISM FOR FILE -FABRIC LOOMS.

SPECIFICATION forming part of Letters Patent No. 651,321, dated June 5, 1900.

Application filed December 31,1897. Serial No. 665,142. (No model.)

T0 at whom it may concern.-

Be it known that I, CLINTON ALVORD, a citizen of the United States, and a resident of Worcester, in the county of Worcester and State of Massachusetts, have invented a new and useful Improvement in Let-Off Mechanism for Looms, of which the following is a specification.

The object of my invention is to provide a let-01f mechanism for looms by which the warp shall be delivered at a constant speed and uniform tension and by which thespeed of delivery can be determined before the warp passes to the shedding mechanisms. My invention is especially designed for looms employing a printed warp; and my invention consists in certain novel features of construction of my improvements, as will be hereinafter fully described.

Referring to the drawings, Figure 1 is a side elevation of the operative portions of a let-off mechanism of a loom embodying my invention, the supporting-framework having been omitted, but with the parts shown in their proper relative positions. Fig. 2 is a front elevation of the Warp-beam and automatic friction mechanism looking the direction of the arrow a, Fig. 1; and Fig. 3 represents a portion of the sand-roll 18 and connected acmating-gearing.

In the accompanying drawings, 1 denotes a warp-beam attached to a shaft 2, supported in suitable framework and restrained from turning in its bearings by the friction-straps 3, which partially inclose friction wheels 4, attached to the shaft 2 of the warp-beam. The straps 3 are attached at one end to fixed pins 5, held in the framework, and at their other end to the short arms 6 of be1l-crank lovers 7, which are pivoted in the framework at 8. The long arms 9 of the bell-crank levers 7 hang vertically and-carry a roll 10, journaled in their lower ends. Each of the arms 9 is also provided with a short rearwardly-projecting arm 11, to the ends of which I pivot bell-crank levers 12, having long arms 13,; carrying weights 14, adjustable thereon, and short vertical arms 15, in the lower ends of which I pivot a roll 16.

The arms of the bell-crank levers 12 are provided on their front edges with a projection 17, arranged to strike the arms 9 of the bell-crank lovers 7 and thereby limit the motion of the bell-crank levers 12 in one direction.

In front of the rolls 10 and 16 1 place a larger roll or drum 18, journaled in the framework of the loomand having its periphery preferably roughened by the application of sand or emery and designated as the sand-roll. The sand-roll 18 is rotated intermittently by an actuating mechanism operatively connecting the sand-roll with the moving parts of the loom and consisting in the present instance of a gear 19, attached to the shaft of the sandroll and engaged by a pinion 20 on a shaft 21, carrying a ratchet-wheel 22, which is intermittently rotated by an actuating-pawl 23, carried on a vibrating lever 24, connected by a link with the swinging lay of the loom. (Not shown.) A friction-wheel 26, attached to the shaft 21, is inclosed by a friction-strap 27, attached at its ends to a fixed pin 28, in order to hold the shaft 21 and connected sandroll 18 from turning, except as actuated by the pawl 23.

Below and to the rear of the sand-roll 18 I pivot a pair of bell-crank levers (one of which is shown at 29 in Fig. 1) having long horizontal arms 30, carrying weights 31, adjustable thereon and having short vertical arms 32, in which is journaled a roll 33.

The warp 341 is conducted from the rear side of the warp-beam 1 in front of and over the roll 10 to the rear of and over the roll 16, over the sand-roll 18, and'around the roll 33, journaled in the short arms 32 of the bellcrank levers 29, thence past suitable shedding mechanism (not shown) arranged in the plane of the broken line 35 to the Woven fabric at 36, which in the present instance is represented as a pile fabric, having loops 37 upon its upper surface produced by the insertion of wires at stated intervals in the woven fabric in the usual and well-known manner. In Fig. 1 two additional warps 38 and 39 are represented as passing, respectively, over rolls 40 and 11. The warps 38 and 39 are employed to form the body of the fabric, and the warp 34, which has been previously printed in suitably-arranged colors to constitute the desired pattern, is employed to form the face of the woven fabric.

As the printed warp on beam 1 has been previously printed in a variety of colors arranged at stated intervals and with the warp under a certain tension, it is necessary that the printed warp should be delivered at such speed and tension that the several colors shall be presented at the desired intervals, so that when the printed warp has been incorporated in the fabric in the operation of weaving the colors shall register accurately with the desired pattern, and this I am able to accomplish with great accuracy and nicety of adlines 42 on a strip of paper or thin cardboard 43 and wrapping the same around the end of the sand-roll beneath one or more springclips 44, which serve to retain the cardboard in position and allow it to be exchanged for different graduated scales when desired.

The periphery of the sand-roll 18 should of course be a multiple of the spaces between the parallel lines 42, and as the sand-roll is intermittently rotated the printed,warp,which incloses half the periphery of the roll, is carried with the roll and drawn oil? the warpbeam owing to the bight of the yarn upon the roughened surface of the roll, and the graduated scale also moves with the roll and at a uniform speed with the warp, enabling the operator to determine whether the proper tension is applied to the warp to cause the colored spots to continue to pass over the sand-roll in accurate registration with the lines 42. The bell-crank levers 7, to which the friction-straps 3 are attached, are so arranged that the weight of the bell-crank levers 12, with their weighted arms 13, will serve to draw the friction-straps 3 closely against the friction-wheels 4 and cause them to act as a brake upon the warp-beam 1. As the warp is drawn forward by the intermittent rotation of the sand-roll 18 a pulling strain is exerted upon the roll 16,'holding the short projections 17 against the arms 9 of the bell-crank levers 7, as shown in Fig. 1. The forward movement of the roll 16 when the projections 17 are in contact with the arms 9 of the bell-crank levers 7 will of course serve to rock the bell-crank lever 7 and release the friction-straps 3, thereby allowing the warp beam 1 to turn and deliver warp. As the rocking of the bell-crank lever 12 must raise the weighted arms 13, the tension upon the yarn between the sand-roll and warp-beam can be adjusted by moving the weights 14 upon the arms 13, enabling that tension to be secured which will cause the spots of color to register accurately with the lines 42 on the scale 43, applied to the rotating sand-roll. For example, if the colors in the warp fall back of the lines 42 as the weaving goes on the tension is too great, and the weights 14 should be moved in on the arms 13. If, on the other hand, thecolors gain on the lines as the sand-roller rotates, the tension upon the Warp is too small and the weights 14 should be moved nearer the ends of the arms 13. A few revolutions of the sand-roll will be suflicient to enable the proper tension to be secured, when the mechanism will thereafter deliver the warp without further adjustment.

, \Vhenever a wire is inserted in the fabric, a greater length of the printed warp 43 is required in order to cover the wire and form the pile, and this extra length of warp is pro. vided for and a uniform tension maintained by means of the roll 33, which is journaled in the rocking bell-crank levers 29, the insertion of the wire causing the roll to swing forward and lift the weighted arms 30, which fall and carry the roll 33 back to take up any slack in the warp.

.The operation of my improved let-off mechanism is as follows: A graduated scale hav-' ing the proper spacing between its lines to correspond with the spaces occupied by the spots of color in the warp when under proper tension is placed upon a sand-roll the periphcry of which is a multiple of the spaces on the scale, and the sand-roll is arranged to be intermittently turned by its actuating mechanism and draw oii. the proper amount of warp from the warp-beam 1 to correspond with the speed of the take-up mechanism. The passage of the warp over the sand-roll is then watched and the Weights 14 adjusted on the arms 13 to secure the requisite tension to cause the spots of color to correspond with the spaces on the graduated scale. The weights 31 are then adjusted on the arms 30 to secure the proper tension required in weaving. As the weaving proceeds the delivery of warp from beam 1 will proceed at a speed and tension which insures the accurate registration of the colors of the printed warp 34 with the desired pattern, and there will be no appreciable movement of the bell-crank levers 12, as the slightest increase in the tension of the warp between the sand-roll and warp-beam 1 will serve to move the bell-crank levers 7, and the slighest movement of the bell-crank levers 7 will release the warp-beam 1, thereby maintaining a uniform tension in the warp which is measured by the force required to counterbalance the Weights 14.

What I claim as my invention, and desire to secure by Letters Patent, is

1. In a let-cit mechanism for looms, the combination with a Warp-beam containing a printed warp, of a roll arranged to rotate at the same speed as the warp as it is withdrawn from said beam in the operation of weaving, and a graduated scale on the periphery of said roll, said scale corresponding with the spaces of color on said warp, whereby the tension of the yarn is ascertained as it passes over said roll, substantially as described.

2. In a let-off. mechanism for looms, the combination with a warp-beam, of. a roll in contact with the warp as it is withdrawn from said beam, a graduated scale applied to the periphery of said roll, means for rotating said roll at a predetermined speed, and means for controlling the tension of the warp as it is delivered from the beam to said roll, substantially as described.

3. In a let-0d mechanism for looms, the combination with a warp-beam, of a roll in contact with the warp as it is withdrawn from said beam, a graduated scale applied to the periphery of said roll, means for rotating said roll at a predetermined speed corresponding with the movement of the warp, means for regulating the tension of the warp between the warp-beam and said roll and a take-up device between said roll and the shedding mechanism of the loom, substantially as described.

4. In a let-off mechanism for a loom, the combination with a warp-beam of a friction device for checking the rotation of the beam, means for withdrawing the warp from said beam ata predetermined speed and comprising a roll in contact with the warp, means controlled by the tension of the warp for regulating the friction device and releasing the warp-beam, and a graduated scale applied to the periphery of said roll, substantially as described.

5. In a let-off mechanism for looms, the combination with a warp-beam of a roll in contact with the warp as it is withdrawn from the beam, means for rotating said roll at a predetermined speed corresponding with the movement of the warp, a graduated scale corresponding to the periphery of said roll and means for detachably attaching said scale to said roll, substantially as described.

6. 1n alet-off mechanism for looms the combination with a warp -beam containing a printed warp, of a feed-roll for drawing the warp from the beam, means for rotating said roll at a predetermined speed and a graduated scale, applied to the periphery of said roll, corresponding in spacing to the printed spots of the warp, substantially as described.

CLINTON ALVORD. Witnesses:

RUFUS B. FOWLER, M. 0. PRICE. 

